﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Numerics;

namespace RSA
{
    public partial class Form2 : Form
    {
        private String namafile;

        public Form2()
        {
            InitializeComponent();
        }

        uint rightrotate(uint bil, int n)
        {
	        uint a = bil >> n, b = bil & (((uint)1 << n)-1);
	        return (a | (b << (32 - n)));
        }

        char heksa(int x)
        {
            if (x < 10)
                return (char)(x + 48);
            return (char)(x + 55);
        }

        uint abs(int a)
        {
	        if (a < 0)
		        return (uint)(0-a);
	        else
		        return (uint)a;
        }

        string SHA(string awal)
    {
	    uint a, b, c, d, e, f, g, h, maj, ch, t1, t2;
        int i, j;
	    ulong length, plus;
	    string hasil = "";
	    //Initialize variables (first 32 bits of the fractional parts of the square roots of the first 8 primes 2..19):
	    uint[] H = {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
	    //Initialize table of round constants (first 32 bits of the fractional parts of the cube roots of the first 64 primes 2..311):
	    uint[] k = {0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
				     0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
				     0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
				     0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
				     0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
				     0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
				     0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
				     0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2};
	    //Pre-processing:
	    length = (ulong)awal.Length;
	    awal += (char)(1 << 7);
	    plus = (length+1) % 64;
	    if (plus <= 56)
		    plus = 56-plus;
	    else
		    plus = 120-plus;
	    for (i=0; i<(int)plus; ++i)
		    awal += (char)0;
	    for (i=64; i>=8; )
	    {
		    i -= 8;
		    awal += (char)(((length << 3) >> i) & 255);
	    }
	    length += plus+9;
	
	    //Process the message in successive 512-bit chunks:
	    uint[] w, s;
        w = new uint[64];
        s = new uint[2];
	    for (j=0; j<(int)length; )
	    {
		    for (i=0; i<16; ++i)
		    {
			    w[i] = (abs(awal[(int)j]) << 24) | (abs(awal[(int)++j]) << 16) | (abs(awal[(int)++j]) << 8) | (abs(awal[(int)++j]));
			    ++j;
		    }
		
		    //Extend the sixteen 32-bit words into sixty-four 32-bit words:
		    for (i=16; i<64; ++i)
		    {
			    s[0] = rightrotate(w[i-15], 7) ^ rightrotate(w[i-15], 18) ^ (w[i-15] >> 3);
			    s[1] = rightrotate(w[i-2], 17) ^ rightrotate(w[i-2], 19) ^ (w[i-2] >> 10);
			    w[i] = w[i-16] + s[0] + w[i-7] + s[1];
		    }

		    //Initialize hash value for this chunk:
		    a = H[0];
		    b = H[1];
		    c = H[2];
		    d = H[3];
		    e = H[4];
		    f = H[5];
		    g = H[6];
		    h = H[7];
		
		    //Main loop:
		    for (i=0; i<64; ++i)
		    {
			    s[0] = rightrotate(a, 2) ^ rightrotate(a, 13) ^ rightrotate(a, 22);
			    maj = (a & b) ^ (a & c) ^ (b & c);
			    t2 = s[0] + maj;
			    s[1] = rightrotate(e, 6) ^ rightrotate(e, 11) ^ rightrotate(e, 25);
			    ch = (e & f) ^ ((~ e) & g);
			    t1 = h + s[1] + ch + k[i] + w[i];

			    h = g;
			    g = f;
			    f = e;
			    e = d + t1;
			    d = c;
			    c = b;
			    b = a;
			    a = t1 + t2;
		    }

		    //Add this chunk's hash to result so far:
		    H[0] = H[0] + a;
		    H[1] = H[1] + b;
		    H[2] = H[2] + c;
		    H[3] = H[3] + d;
		    H[4] = H[4] + e;
		    H[5] = H[5] + f;
		    H[6] = H[6] + g;
		    H[7] = H[7] + h;
	    }

	    //Produce the final hash value (big-endian):
	    for (i=0; i<8; ++i)
	    {
		    for (j=32; j>=4; )
		    {
			    j -= 4;
			    hasil += heksa((int)((H[i] >> j) & 15));
		    }
		    hasil += " ";
	    }
	    return hasil;
    }

        private String open()
        {
            Stream myStream = null;
            OpenFileDialog openFileDialog1 = new OpenFileDialog();

            openFileDialog1.InitialDirectory = "c:\\";
            openFileDialog1.FilterIndex = 4;
            openFileDialog1.RestoreDirectory = true;
            String result = "";
            int c;

            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                try
                {
                    if ((myStream = openFileDialog1.OpenFile()) != null)
                    {
                        textBox3.Text = openFileDialog1.FileName;
                        namafile = openFileDialog1.SafeFileName;
                        byte[] buffer = new byte[myStream.Length];
                        myStream.Read(buffer, 0, buffer.Length);
                        String text = Encoding.UTF8.GetString(buffer);
                        text=text.Replace("\0","\\0");
                        return text;
                        /*using (myStream)
                        {
                            int i = 0;
                            // Insert code to read the stream here.
                            while ((c = myStream.ReadByte()) != -1)
                            {
                                //bytemasukan[i] = c;
                                result += (char)c;
                                //i++;
                            }
                            MessageBox.Show("Error: Could not read file from disk. Original error: " + result.Length);
                        }*/
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
                }
            }
            return result;
        }


        private void save(String s)
        {
            Stream myStream;
            SaveFileDialog saveFileDialog1 = new SaveFileDialog();
            if (textBox3.Text == "")

                saveFileDialog1.InitialDirectory = "c:\\";
            else
                saveFileDialog1.InitialDirectory = textBox3.Text;

                saveFileDialog1.Filter = "pri files (*.pri)|*.pri|pub files (*.pub)|*.pub|txt files (*.txt)|*.txt|All files (*.*)|*.*";
            saveFileDialog1.FilterIndex = 4;
            saveFileDialog1.RestoreDirectory = true;

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if ((myStream = saveFileDialog1.OpenFile()) != null)
                {
                    // Code to write the stream goes here.
                    int i, l = s.Length;
                    for (i = 0; i < l; ++i)
                        myStream.WriteByte((Byte)s[i]);
                    myStream.Close();
                }
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            textBox1.Text = open();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            String text = textBox1.Text.Replace("\\0", "\0");
            save(text);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            DateTime dt = DateTime.Now;
            String t = dt.ToString("T");
            save("" + namafile + Environment.NewLine + t + Environment.NewLine + textBox2.Text);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            String text = textBox1.Text.Replace("\\0","\0");
            textBox2.Text = SHA(text);
        }

        private void button5_Click(object sender, EventArgs e)
        {
            String text = open();
            String sha = SHA(text);
            if (textBox2.Text.Equals(sha))
                MessageBox.Show("sama");
            else
                MessageBox.Show("tidak sama");
        }

    }
}
